function [r, c] = houghpixels(f, theta, rho, rbin, cbin)
% HOUGHPIXELS Compute image pixels belonging to Hough transform bin.
%   [R, C] = HOUGHPIXELS(F, THETA, RHO, RBIN, CBIN) computes the
%   row-column indices (R, C) for nonzero pixels in image F that map
%   to a particular Hough transform bin, (RBIN, CBIN).  RBIN and CBIN
%   are scalars indicating the row-column bin location in the Hough
%   transform matrix returned by function HOUGH.  THETA and RHO are
%   the second and third output arguments from the HOUGH function.
    
[x, y, val] = find(f);
x = x - 1; y = y - 1;
    
theta_c = theta(cbin) * pi / 180;
rho_xy = x*cos(theta_c) + y*sin(theta_c);
nrho = length(rho);
slope = (nrho - 1)/(rho(end) - rho(1));
rho_bin_index = round(slope*(rho_xy - rho(1)) + 1);
    
idx = find(rho_bin_index == rbin);
    
r = x(idx) + 1; c = y(idx) + 1;

    
end % ending function